A newly created non-profit organization sued the U.S. Securities and Exchange Commission on Wednesday in an effort to force the agency to adopt rules requiring companies to disclose political contributions.
The Campaign for Accountability said it was formed to use "research, litigation and communications to expose misconduct and malfeasance in public life."
The SEC has been under mounting pressure from liberal groups, as well as a handful of law professors, to enact rules requiring companies to tell investors about campaign contributions.
The efforts were sparked by the Supreme Court's 2010 Citizens United decision, which loosened campaign finance rules and opened the floodgates to millions of dollars in political spending by businesses and individuals.
The decision inspired a new wave of politically focused non-profit groups that are not required to disclose the identity of their donors.
SEC Chair Mary Jo White has said the agency is not going to write rules on corporate spending, and instead would focus on completing regulations required by Congress in 2010 and 2012.
The lawsuit marks the latest effort to force the SEC into action.
Last year, another group called the Corporate Reform Coalition held a news conference outside SEC headquarters to make similar demands.
Earlier this year, members of the coalition also launched a public relations blitz titled "Have you seen Mary Jo White?"
The campaign features posters that depict White as a comic book style super hero rushing to rescue investors in the dark about how corporations spend money on political issues.
The posters were placed in Union Station, the metro stop next door to the SEC's headquarters.
The Campaign for Accountability said its lawsuit against the SEC was filed in the U.S. District Court for the District of Columbia on behalf of Steve Silberstein, who filed a rule-making petition to the SEC last year.
The group says the agency "ignored" his request and violated federal laws that govern the rule-making process.
In 2013, Silberstein sued Aetna Inc as a shareholder, saying it failed to accurately reveal its political donations.
The case was later dismissed.
An SEC spokesperson did not immediately respond to a request for comment on the lawsuit.
